Visoelastic relaxation of Venusian coronae and mountain belts: Constraints on global heat flow and tectonism

Venus differs from Earth in that water is essentially absent and its surface temperatures are about 470 K higher. The competing effects of high surface temperature and dry lithologies on the long-term history of surface topography have been studied using the finite-element method. The relaxation history of surface topographic features, such as coronae and mountain belts, is a function of thermal gradient, crustal thickness and lithology, regional stresses, and basal tractions applied to the lithosphere. In this study, we have examined the relative effects of these factors over a period of 500 Ma (presumed to be the mean age of the venusian surface)

Schools and their communities: pupil and teacher perceptions of community action

In England over the last two decades, there has been a growing interest in the role of English schools in developing, facilitating and supporting young people’s community participation. A number of policy initiatives have sought to build the capacity and opportunities for youth participation. Research suggests, however, that pupils and schools are often prohibited by significant barriers from becoming involved with community activities, particularly those which might occur beyond the school environment itself. In March 2010 the UK Labour government launched a Youth Community Action initiative for England, piloted across five local authorities, which aimed to involve young people of 14-16 years-of-age in community action. Following the UK general election in May 2010, the Conservative-Liberal Democrat coalition government terminated these pilots but was quick to announce the launch and piloting of a National Citizen Service for 16-19 year olds in England. Purpose Drawing on research conducted with participants in one Youth Community Action pilot project, the aim of this study was to explore the perceptions and understandings of young people regarding their involvement in community action activities and how this compared to the perceptions and understandings of the teachers responsible for co-ordinating such activities. Sample In the final synthesis, the sample comprised 614 pupil questionnaires, representing a response rate of 24 percent of the pupils in the 9 participating schools. 11 semi-structured interviews and one focus group interview were conducted with pupils in 6 of the schools, with a further 8 semi-structured interviews conducted with teachers in these 6 schools. Design and methods A questionnaire was administered to pupils participating in the Youth Community Action pilot, enabling an exploration of self-reported behavioural attitudes and perceptions. The data collected was analysed thematically, with an identification of common themes in responses. In addition, factor analysis and a series of Chi² tests of association were carried out. The use of semi-structured interviews, the data from which were analysed thematically, enabled a qualitative exploration of pupils’ and teachers’ self-reported perceptions of community action activities. Results The findings of our questionnaires report that those pupils who know more about their local neighbourhood and community are likely to report greater levels of concern for what happens within it. This suggests that pupils’ learning about their neighbourhoods and community is likely to be beneficial toward developing affective attachments to them. For the pupils in our data-set, simply possessing pro-social behaviours and attitudes was not a sufficient or necessary condition for their community awareness and involvement. It suggests that, at least for a notable number of pupils, active engagement in the community requires cultivation and learning beyond pro-social behaviours. The semi-structured interviews report that pupils identify the school as the key source of information about community engagement opportunities, but also indicate that there is a marked difference in the activities which teachers identify their pupils as having undertaken, and the ability of pupils to vocalise these themselves. A further notable finding was a focus on the practical (time, distance, age-constraints) and social (peer-pressure) barriers to community action activities to the exclusion of specifically educational (lack of understanding and skills) barriers. Conclusions Results from this study suggest that schools represent an important source for pupils’ community involvement, but that in our sample pupils often lack the vocabulary with which to explain the extent and nature of such engagement. Pupils and teachers identify a range of barriers to and benefits of community involvement, but these do not include a lack of understanding or skills. The research raises important questions in the context of recent policy trends in England

Local Authority Development Collaboratives 2008-09 report

As part of the Study Support (SS) Quality Development Programme (QDP) the DCSF provided via Quality in Study Support (QiSS) a grant to develop collaboratives to support Local Authorities (LAs) working together to measure the impact of study support provision within and across regions. Each region was asked to invite Local Authorities (LAs) to commit time to specific projects alongside colleagues within the two themes under the umbrella of QA and impact measurement. Each group would then submit an action plan and budget which would be approved centrally before funding was approved. As a condition of the grant each participating LA initially was asked to carry out a Study Support self-review based on the criteria developed as part of the national framework for Study Support to demonstrate how the proposed collaborative project addressed developmental needs identified in the self-review. Each participating LA was asked to describe how the impact of the activity was evaluated and outcomes disseminated. In addition they were required to indicate how their ‘Development Collaborative’ (DC) has address staff or organisational or service development or delivery issues. 49 LAs participated in DCs during the year 2008-09 .13 DCs were planned but two withdrew and have not been reported upon compared to 19 undertaken in 2007-08). A number of notable outcomes resulted, ranging from increased involvement of young people as advocated and mentors through to holding a conference aimed at commissioners of services and LA Advisors to highlight the importance of engaging in study support activities

Bereaved relatives' experiences in relation to post mortem: a qualitative exploration in North East Scotland.

When a family is grieving the loss of a member the consideration of post mortem is an additional concern. This study set out to explore how relatives are supported to give authorisation and throughout the post mortem process. Thirteen relatives with varied experiences of a relative's death took part in interviews. Data analysis revealed the post mortem as part of the narrative of the death, with more significance for some than others. Important aspects for relatives were being able to say goodbye properly, and engagement with staff in hospital and procurator fiscal (public prosecution) services in more substantive communicative relationships, rather than only receiving basic information. Relatives valued receiving results they could understand. There may be opportunities, particularly in coroner or procurator fiscal services, for development of roles in liaison between relatives and pathology services, and support for relatives

Reconstructing a model of quintessential inflation

We present an explicit cosmological model where inflation and dark energy both could arise from the dynamics of the same scalar field. We present our discussion in the framework where the inflaton field $\phi$ attains a nearly constant velocity $m_P^{-1} |d\phi/dN|\equiv \alpha+\beta \exp(\beta N)$ (where $N\equiv \ln a$ is the e-folding time) during inflation. We show that the model with $|\alpha|<0.25$ and $\beta<0$ can easily satisfy inflationary constraints, including the spectral index of scalar fluctuations ($n_s=0.96\pm 0.013$), tensor-to-scalar ratio ($r<0.28$) and also the bound imposed on $\Omega_\phi$ during the nucleosynthesis epoch ($\Omega_\phi (1 {\rm MeV})<0.1$). In our construction, the scalar field potential always scales proportionally to the square of the Hubble expansion rate. One may thereby account for the two vastly different energy scales associated with the Hubble parameters at early and late epochs. The inflaton energy could also produce an observationally significant effective dark energy at a late epoch without violating local gravity tests.Comment: 18 pages, 7 figures; added refs, published versio

Nitrogen deposition does not enhance Sphagnum decomposition

Long-term additions of nitrogen (N) to peatlands have altered bryophyte growth, species dominance, N content in peat and peat water, and often resulted in enhanced Sphagnum decomposition rate. However, these results have mainly been derived from experiments in which N was applied as ammonium nitrate (NH4NO3), neglecting the fact that in polluted areas, wet deposition may be dominated either by NO3- or NH4+. We studied effects of elevated wet deposition of NO3- vs. NH4+ alone (8 or 56 kg N ha(-1) yr(-1) over and above the background of 8 kg N ha(-1) yr(-1) for 5 to 11 years) or combined with phosphorus (P) and potassium (K) on Sphagnum quality for decomposers, mass loss, and associated changes in hummock pore water in an ombrotrophic bog (Whim). Adding N, especially as NH4+, increased N concentration in Sphagnum, but did not enhance mass loss from Sphagnum. Mass loss seemed to depend mainly on moss species and climatic factors. Only high applications of N affected hummock pore water chemistry, which varied considerably over time. Overall, C and N cycling in this N treated bog appeared to be decoupled. We conclude that moss species, seasonal and annual variation in climatic factors, direct negative effects of N (NH4+ toxicity) on Sphagnum production, and indirect effects (increase in pH and changes in plant species dominance under elevated NO3- alone and with PK) drive Sphagnum decomposition and hummock C and N dynamics at Whim. (C) 2016 Elsevier B.V. All rights reserved.Peer reviewe

Decentralised Learning MACs for Collision-free Access in WLANs

By combining the features of CSMA and TDMA, fully decentralised WLAN MAC schemes have recently been proposed that converge to collision-free schedules. In this paper we describe a MAC with optimal long-run throughput that is almost decentralised. We then design two \changed{schemes} that are practically realisable, decentralised approximations of this optimal scheme and operate with different amounts of sensing information. We achieve this by (1) introducing learning algorithms that can substantially speed up convergence to collision free operation; (2) developing a decentralised schedule length adaptation scheme that provides long-run fair (uniform) access to the medium while maintaining collision-free access for arbitrary numbers of stations

Dark energy from scalar field with Gauss Bonnet and non-minimal kinetic coupling

We study a model of scalar field with a general non-minimal kinetic coupling to itself and to the curvature, and additional coupling to the Gauss Bonnet 4-dimensional invariant. The model presents rich cosmological dynamics and some of its solutions are analyzed. A variety of scalar fields and potentials giving rise to power-law expansion have been found. The dynamical equation of state is studied for two cases, with and without free kinetic term . In both cases phenomenologically acceptable solutions have been found. Some solutions describe essentially dark energy behavior, and and some solutions contain the decelerated and accelerated phases.Comment: 21 page

Stress corrosion in titanium alloys and other metallic materials

Multiple physical and chemical techniques including mass spectroscopy, atomic absorption spectroscopy, gas chromatography, electron microscopy, optical microscopy, electronic spectroscopy for chemical analysis (ESCA), infrared spectroscopy, nuclear magnetic resonance (NMR), X-ray analysis, conductivity, and isotopic labeling were used in investigating the atomic interactions between organic environments and titanium and titanium oxide surfaces. Key anhydrous environments studied included alcohols, which contain hydrogen; carbon tetrachloride, which does not contain hydrogen; and mixtures of alcohols and halocarbons. Effects of dissolved salts in alcohols were also studied. This program emphasized experiments designed to delineate the conditions necessary rather than sufficient for initiation processes and for propagation processes in Ti SCC